KR20080099747A

KR20080099747A - Girder for preventing damage by welding combination between bearing on pier

Info

Publication number: KR20080099747A
Application number: KR1020070045707A
Authority: KR
Inventors: 엄광진
Original assignee: (주)삼현피에프
Priority date: 2007-05-10
Filing date: 2007-05-10
Publication date: 2008-11-13

Abstract

The present invention relates to a girder which is welded and coupled to a seating device, comprising: an embedded iron plate fixed to the bottom of the girder such that at least one surface of the girder is exposed to be fixed by welding to the seating device; A buffer part interposed between the embedded iron plate and the concrete at an interface around the welded portion of the embedded iron plate; Including, in the process of joining the girder by the welding device and the welding device to prevent the welding portion is transmitted to the concrete of the girder to block the buffer around the embedded sheet, and at the same time defects such as cracking of the concrete caused by thermal deformation of the embedded sheet Provides girders to minimize.

Description

GIRDER FOR PREVENTING DAMAGE BY WELDING COMBINATION BETWEEN BEARING ON PIER}

1 is a side cross-sectional view of a conventional girder mounted by welding with alternating seating devices.

2 is an enlarged side cross-sectional view of portion 'A' of FIG.

3 is a cross-sectional view taken along line III-III of FIG.

Figure 4 is a side cross-sectional view of the girder in accordance with an embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4. FIG.

6 is a bottom view of the composite girder of FIG.

Figure 7 is a cross-sectional view of the girder according to another embodiment of the present invention

** Description of symbols for the main parts of the drawing **

77: welding heat transfer direction 88: stranded anchorage position

100,200: Girder 110: Steel

120: concrete 130,230: point reinforcement

140: embedded iron plate 150: buffer

The present invention relates to a girder coupled by welding with a bridge device, and more particularly, in order to stably mount a concrete girder or a rigid composite girder to a bridge device on a bridge or alternating bridge, The present invention relates to a connection structure of a scaffolding device that prevents cracking in concrete due to welding heat during mutual welding coupling.

In general, the concrete girders can support a relatively high compressive stress, but are vulnerable to the tensile stress, the reinforcement is built inside to prevent the concrete from being destroyed by the tensile stress from the outside, the action of the external force In order to offset the tensile stress to a predetermined limit, the stress distribution and magnitude are artificially determined in advance, and the strength may be introduced using high strength steel (commonly referred to as "tension material"). In order to achieve longer spans with lower mold heights, I-shaped steels may be installed in concrete.

However, the stress acting on the concrete cross section in the girder is not only generated by the physical external force, but also in the process of mounting the concrete girder fabricated on the pier or the alternating bridge device.

That is, as shown in Figs. 1 to 3, when the concrete girder or the composite girder 20 is mounted on the bridge device 30 on the bridge or bridge 10, the upper plate 35 of the bridge device 30 ) And the embedded steel plate 24 of the girder 20 are welded to each other. During this process, the concrete girder 20 generates an axially parallel deformation due to thermal expansion together with the bending deformation 24 ′ of the embedded steel plate 24. As a result, cracks are generated in the concrete 22 surrounding the embedded steel plate.

In more detail with respect to the composite girder, the composite girder 20 is a concrete girder in which the concrete 22 is poured and cured so as to surround the I-shaped steel 21, and is in contact with the seat device 30 ( An embedded iron plate 24 is embedded at the bottom of the plate 20 to expose one surface of the plate-shaped steel, and connects between the steel 21 and the embedded iron plate 24 so as to safely transmit its own weight or external force to the steel 21. It consists of a plurality of reinforcing plates (23).

In addition, the teaching device 30 absorbs vibrations or shocks transmitted from the girder 20 and allows a slight deflection displacement, and a suction part 31 below the suction part 31. On the lower plate 32 coupled with the base plate 33 fixed by the anchor bolt 34 so as to fix the device 30 on the piers or shifts 10, and the upper part of the suction part 31. It consists of an upper plate 35 coupled to the suction part 31.

Here, the embedded steel plate 24 of the girder 20 is an upper portion of the seating device 30 so as to keep the girder 20 firmly mounted on the top of the seating device 30 and to prevent relative movement therebetween. It is fixed integrally by the plate 35 and the welding 40. The welding heat between the embedded iron plate 24 and the upper plate 35 involved in this process is distributed to the surroundings. At this time, the embedded iron plate 24 embedded in the concrete causes axial deformation due to bending deformation or thermal expansion. Thus, the concrete 22 surrounding it has a problem such as cracking, and the welding heat transmitted from the buried iron plate 24 has a problem of thermal expansion of the concrete 24 to cause additional defects such as peeling.

In addition, as shown in FIG. 3, in order to make the structural efficiency of the steel 21 more rational, when the lower flange 21b is formed smaller than the upper flange 21a, the point reinforcement 23 has a narrow width. As the steel 21 and the embedded iron plate 24 are formed in a tight cross section from the flange 21b at a tight interval, the embedded iron plate 24 is easily deflected due to the heat of welding. 24 ') also occurred.

The present invention has been made in order to solve the problems as described above, the welding plate and the coupling plate of the upper plate and the girders of the girder in order to stably mount the concrete girder or the composite girder to the stirrer device on the bridge or alternator The purpose of the present invention is to minimize performance degradation such as cracking of concrete due to welding heat generated in the process.

In addition, another object of the present invention is to provide a buried steel sheet structure of a concrete girder and a composite girder to minimize the bending deformation even when using a thin sheet steel sheet.

In addition, the present invention is a structure in which the PS steel is embedded in the concrete, while preventing the bending deformation of the embedded steel sheet in the process of welding bonding the seating apparatus and the embedded steel sheet to prevent interference with the arrangement of the PS steel anchorages It is done.

The present invention is a bridge girders mounted on the bridge device on the bridge or alternator in order to achieve the object as described above, buried buried fixed so that at least one surface is exposed to the bottom surface of the girder to be fixed by the bridge device and welding. Iron plate; A buffer part interposed between the embedded iron plate and the concrete at an interface around the welded portion of the embedded iron plate; It provides a concrete girder or a composite girder characterized in that it comprises a.

This prevents the thermal expansion deformation of the embedded steel sheet and the heat of the weld from being transmitted to the concrete formed around the embedded steel sheet by the buffer part around the welded portion in the process of joining the girder by welding with the abutment device. By doing so, it is to minimize the occurrence of functional degradation phenomenon, such as cracking and peeling of concrete generated in the installation step of the girder.

Here, since the chair apparatus is generally welded in a closed curve shape surrounding the embedded steel plate, the buffer part is preferably formed to surround the circumference of the embedded steel plate. Through this, it is possible to effectively prevent the transfer of the heat generated in the welding process for coupling the bridge device and the girder and the deformation of the buried plate to the concrete of the girder.

At this time, the buffer portion is formed of a viscoelastic material having a low thermal conductivity while accommodating expansion displacement by heat, such as rubber and silicone. On the other hand, the buffer portion may not be a regular shape but may be formed of a material such as cotton formed of tough fibers.

In addition, when the girder is formed of a steel composite girder synthesized with steel, a trapezoidal point reinforcement having a larger cross section is formed between the embedded steel plate and the steel as the steel plate approaches the embedded steel plate. As a result, the bending deformation of the embedded steel sheet generated by the welding heat is physically constrained to effectively suppress the bending deformation of the embedded steel sheet in the outward direction, and at the same time, when the PS steel is embedded in the concrete, the embedded steel sheet is installed at the concrete end. Interference with the anchorage can also be avoided.

In addition, since the embedded steel sheet is physically constrained by being welded to the point reinforcement including a trapezoidal shape, the bending phenomenon is minimized even when the thickness of the embedded steel plate is formed to be thinner than the conventional one, and the distance d between the point reinforcement as compared to the prior art. You can place it farther away. This is because the conventional narrow arrangement of the reinforcement while using a narrow reinforcement to secure the effective area for connecting the steel, rebar assembly or concrete casting failure occurs, the spacing between the point reinforcement is difficult to weld difficult It was solved at once.

On the other hand, the point reinforcing member is formed with an inward inflection point at the edge of the cross-section, the cross-section is gradually wider as the steel plate approaches the embedded steel plate, the cross section may be formed near the steel. That is, the point reinforcing material is not limited to being formed in a trapezoidal shape, and if the trapezoidal shape is included in a form in which the trapezoid is in contact with the embedded steel sheet, the above-described effect can be obtained. Through this, it is possible to effectively prevent the bending deformation to the outside of the embedded steel sheet, and to prevent the anchorage of the strand wire and the point reinforcement for introducing the prestress to the concrete to interfere with each other.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, in describing the present invention, a detailed description of known functions or configurations will be omitted to clarify the gist of the present invention.

Figure 4 is a side cross-sectional view of the composite girder according to an embodiment of the present invention, Figure 5 is a cross-sectional view taken along the cutting line V-V of Figure 4, Figure 6 is a bottom view of the composite girder of Figure 4;

As shown in the drawings, the composite girder 100 according to an embodiment of the present invention is a steel 110 formed of an I-shaped steel with an upper flange larger than a lower flange, and concrete formed to surround the steel 110. The portion 120, the point reinforcement 130 and the one end is welded to the steel 110 and one end to securely transfer the load applied from the outside to the steel 110, and the concrete portion 120 so that one surface is exposed to the outside Buried iron plate 140 buried and welded to the other end of the point reinforcement 130, a buffer 150 formed of a rubber material to surround the circumference of the embedded iron plate 140, and reinforcing steel reinforced to reinforce the load capacity of concrete (Not shown) and a tension member (not shown) which introduces an internal force in advance so that the tensile stress acting by the external force can be canceled to a predetermined limit.

The steel 110 is embedded in the concrete portion 120 to reinforce the stiffness of the girder 110, the lower flange is formed of I-shaped steel smaller than the upper flange to maximize the cross-sectional efficiency of the girder 110 do.

The point reinforcing member 130 is formed in a trapezoidal shape that the edge 130a extending downward from the steel 110 as shown in FIG. 5 is welded to the embedded iron plate 140, the embedded iron plate 140, The bending strain 24 'bent by this welding heat is restrained. At this time, in order to restrain the bending displacement of the embedded steel plate 140 to the maximum by the point reinforcement 130, the point reinforcement 130 is the end of the embedded steel plate 140 in the area in contact with the embedded steel plate 140 ( The edge 130a of the cross section is formed to reach 140a).

As a result, the bending deformation 24 ′ of the embedded steel plate 140 is reinforced by heat generated by welding between the upper plate 35 of the seating device 30 and the embedded steel plate 140 of the girder 100. Since the 130 is physically constrained, the bending deformation of the embedded iron plate 140 may be minimized. In addition, since the steel reinforcement 110 can be more effectively supported by the point device 30 through the point reinforcement 130, the installation interval d of the point reinforcement 130 can be larger.

On the other hand, the cross-section of the point reinforcement 130 may be formed in a rectangular cross-section, if the cross-section of the point reinforcement 130 is formed in a rectangular cross section and the anchorage 88 of the tension member installed in the lower edge of the concrete girder 100 and Since the interference is generated, the edge of the cross section of the point reinforcement 130 is formed in a trapezoidal shape formed by the inclined surface (130a) as shown in FIG.

As shown in FIG. 4, the buried iron plate 140 is exposed at one surface of the bottom surface of the concrete girder 100, and is coupled to the upper plate 35 of the bridge device 30 by welding 40.

The buffer unit 150 is formed of a viscoelastic material such as rubber or silicon having a low thermal conductivity so as to surround the circumference of the embedded iron plate 140 as shown in FIGS. 4 and 6. This prevents the welding heat between the seating device 30 and the embedded steel plate 140 from being transmitted to the concrete unit 120 by a rubber or silicon buffer, and at the same time, a plane parallel to the bridge of the embedded steel plate. The thermal expansion displacement in the direction can be accommodated.

On the other hand, in order to maximize the blocking effect of the heat transfer and the heat deformation by the buffer unit 150 as described above, although not shown in the figure, all the space between the concrete portion 120 and the embedded iron plate 140 is buffered It may be formed to fill with the portion 150.

Girder 100 according to an embodiment of the present invention configured as described above, even if coupled by welding with the upper plate 35 of the device 30 installed on the bridge or alternator 10, the transmission path of the welding heat 77 By blocking the buffer unit 150, it is possible to prevent the damage by the welding heat at the 'X' point where the damage was conventionally generated by the welding heat. In addition, the point reinforcing material 140 from the steel 110 to the embedded steel plate 140 is formed in a trapezoidal shape whose cross section gradually increases as the approaching steel plate 140 is approached, so that the embedded steel plate 140 by the heat of welding By physically suppressing the bending deformation, it is possible to prevent the concrete damage of the inner (Y) region of the embedded iron plate 140.

On the other hand, Figure 7 is a cross-sectional view of a steel composite girder according to another embodiment of the present invention. The girder 200 according to another embodiment of the present invention shown in FIG. 7 differs only in the shape of the point reinforcement 230 as compared to the above-described embodiment 100, and the rest of the configuration is one. All of the configurations of the embodiment 100 are the same or similar. That is, the point reinforcement member 230 of the concrete girder 200 according to another embodiment of the present invention is formed with an inward inflection point 231 at the edge 230a of the cross-section, embedded steel plate 140 from the steel 110 As the cross-section approaches, the cross-section becomes wider and wider, and there is a region where the cross-section is uniformly extended near the steel 110, so that the cross-section in this region is smaller than the point reinforcement 130 in one embodiment. This effectively suppresses the bending deformation 24 'to the outside of the embedded iron plate 140, and at the same time the position of the anchorage 88 of the strand wire that introduces the prestress into the concrete part 120 is different from the point reinforcement 230. To avoid interference more effectively.

In the above, the preferred embodiments of the present invention have been described by way of example, but the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope described in the claims. That is, in the embodiment of the present invention, only the girder girder has been described as an example, but the girder in which the embedded iron plate welded to the stabilization device is recessed and fixed to at least a portion of the girder has various shapes such as concrete girder in addition to the girder girder. It is obvious that the present invention can also be applied.

As described above, the present invention, the bridge girders mounted on the bridge device on the bridge or alternating, embedded steel plate fixed to at least one surface exposed to the bottom surface of the girder to be fixed by the bridge device and welding; A buffer portion formed around a welded portion between the embedded iron plate of the girder and the pedestal device; Including, in the process of joining the girder by the welding device and the welding device, the thermal expansion deformation of the buried sheet and the welding heat generated during welding is blocked by the buffer portion around the embedded sheet to prevent the occurrence of cracks, etc. Provide the girder.

In addition, according to the present invention, the trapezoidal point reinforcement having a larger cross section becomes closer to the embedded steel plate and is physically constrained by forming the connection between the embedded steel plate and the steel, thereby effectively preventing the deformation of the embedded steel plate by the heat of welding. At the same time, interference with the anchorages installed in the concrete ends can also be avoided.

And, since the embedded steel plate is physically constrained by the point reinforcement having a trapezoidal shape, even if the embedded steel plate is formed of a steel plate having a thinner thickness than the conventional one, the bending deformation phenomenon due to the welding coupling can be minimized. The spacing (d) between them can be arranged further, making it easier to assemble the reinforcing bars, greatly reducing the incidence of cavities, etc. during the casting of concrete, and making the welding joint work of the point reinforcement much easier. Has an effect.

Claims

As a bridge girders mounted on bridges or on bridges,

An embedded iron plate fixed to the bottom of the girder so that at least one surface thereof is exposed to the concrete of the girder so as to be fixed by welding with the teaching device;

A buffer part interposed between the embedded iron plate and the concrete at an interface around the welded portion of the embedded iron plate;

Girder, characterized in that configured to include.

The method of claim 1,

Girder characterized in that the buffer portion is formed to surround the circumference of the embedded iron plate.

The method of claim 1,

The girder is characterized in that the buffer is formed in the form of wrapping the embedded iron plate to block the contact of the concrete and the embedded iron plate of the girder.

The method of claim 2,

Girder characterized in that the buffer portion is formed of a viscoelastic material.

The method according to any one of claims 1 to 4,

The girder is a composite girder combined with steel,

Girder, characterized in that between the buried iron plate and the steel, the point reinforcing member including a trapezoidal shape that the cross-section is larger as the approach to the embedded iron plate closer.

The method of claim 5,

And the point reinforcement is formed to have an inward inflection point at the edge of the cross section.